Hydrogen gas have been paid attention as a clean fuel for a fuel cell since the hydrogen generates water even so it oxidized with an oxidizing agent and, in recent years, the hydrogen gas attracts much attention as a fuel on the basis of requirement that an energy infrastructure would be switched from fossil fuel to a clean energy in the viewpoints of fossil fuel exhaustion and global warming. Hydrogen has hitherto been generated by electrolysis, charged into a high-pressure vessel, and then transported for use in various places. Accordingly, the use of hydrogen gas needs heavy containers for transportation, needs careful handling due to the flammability thereof, and is not satisfactory in the view of long-term storability thereof.
Accordingly, in the future, it is considered that an apparatus and a method for simply generating hydrogen gas with a clean energy will be required instead of the transportation of hydrogen gas. Further, as for the generation of hydrogen gas, it is considered that a technique for generating hydrogen gas while effectively using a renewable energy will be required instead of the use of a large amount of electricity, which is generated by a method using a huge amount of fossil energy, such as electrolysis of water. Further, it is preferable that an apparatus and a method for generating hydrogen reuse a raw material as much as possible.
There has been known a method for thermally reducing an oxide resource such as a magnesium-containing oxide (magnesium oxide or dolomite) by using arc discharge to reduce the oxide resource at a temperature as high as approximately 1,000 Celsius degrees. And it is thought that hydrogen gas could be obtained by adding water to such the system. However, in consideration of circumstance in that the object for obtaining hydrogen gas is to generate a clean energy for retrenching CO2 and the like, it is considered that the electricity for generating the arc discharge causes an increase of environmental loads in many cases.
Further, various apparatuses and methods for generating hydrogen have been proposed. For example, Japanese Patent Laid-Open No. 2003-313001 (Patent Literature 1) discloses a hydrogen generation method for generating hydrogen by subjecting a hydride to hydrolysis in a sealable vessel where the hydride and water are separated by a member formed at least partially from a water-repellent steam-permeable material having a permeability for steam, while the molecules of the water penetrated through the water-repellent steam-permeable material react with the hydride.
Further, Japanese Patent Laid-Open No. 2003-226502 (Patent Literature 2) discloses a hydrogen generation apparatus for recovering hydrogen generated by a hydrogen recovery means, the hydrogen generation apparatus including: a container for retaining a hydrogen generation fuel consisted of aluminum and an alkali metal or an alkali earth metal; a heating means for melting the hydrogen generation fuel by heat to alloy, the hydrogen generation fuel being retained in the container; and a water supply means for supplying water to the hydrogen generation fuel in the above container.
Further, Japanese Patent Laid-Open No. 2002-69558 (Patent Literature 3) discloses a hydrogen generation apparatus using a hydrogen generation fuel made of an alloy of aluminum and an alkali metal or an alkali earth metal, the hydrogen generation apparatus being provided with a cooling means for cooling the interior of the container, and a hydrogen generation method therewith.
Further, Japanese Patent Laid-Open No. H8-109001 (Patent Literature 4) discloses a hydrogen generation method including the steps of melting a reaction metal body with a heat source, reserving this melted reaction metal body in the bottom of a container while supplying water to the melted reaction metal body to cause a thermo-chemical reaction, and taking the obtained hydrogen out, and discharging the oxidized metal body into outside of the container with a discharge means.
Further, Japanese Patent Laid-Open No. H8-59201 (Patent Literature 5) and Japanese Patent Laid-Open No. H7-109102 (Patent Literature 6) disclose a hydrogen generation method using water contained in a container and a reaction metal body, that reacts electro-thermo-chemically with the water, the method including the steps of supplying the water from the upper part of the reaction metal body, and generating the hydrogen gas due to electro-thermo-chemical reaction of the reaction metal body and the water, and an apparatus thereof.
Further, Japanese Patent Laid-Open No. 2004-231466 (Patent Literature 7) discloses a hydrogen generation material containing aluminum powder of a mixture ratio less than 85 mass % and calcium oxide powder for generating hydrogen from water, and a method and an apparatus for generating hydrogen by using the above material.
The above apparatus and the above methods for generating hydrogen aim to generate hydrogen gas with the use of an electric furnace, electrochemical reaction or a high hydrogen atom containing substance to heat a mixture while the mixture being a hydrogen generation material to realize a high temperature state where the water could be reduced by the metal. In this case, the metal element will oxidize into a metal oxide after the hydrogen generation. However, when the metal oxide is abolished or used for another purpose, the interminable use of the metal element may be require to generate hydrogen and, in case where aluminum is used for example, a total environmental cost including a electric power consumption, the use of a fossil fuel for providing the electricity and the like is not always low.
On the other hand, both oxidization and reduction of a metal element are carried out at a high temperature except to the case where a wet electrochemical method is adopted. In this case, it is considered that the environmental cost including a material cost for hydrogen generation could be extremely retrenched when a hydrogen generation apparatus capable of oxidizing the metal element at a minimum apparatus cost to generate hydrogen, changing the process target and reducing the metal oxide to generate a metal with a minimum change of the apparatus structure, could be provided.
Furthermore, in recent years, environmental problems related to chemical substances are well known so far, for example, nitrogen oxides NOx are required to decline from the viewpoints of natural destruction and structures' degradation due to acid rain generated thereby. Further, carbon dioxide CO2 as a major factor of the global warming is also requested to decline globally. In addition, low cost decomposition and/or conversion methods of particular chemical substances such as dioxin and endocrine disruptor chemicals are also required.
On the other hand, a laser apparatus generates a laser beam mainly by converting an electric energy into a form of light (turns on a lamp) or an electric discharge to pump a laser medium. It is known that such method includes a plurality of energy conversion processes and has a low-energy efficiency (not more than a few percent). The reason may include the fact that an electric energy, which has originally high quality, is converted into light through a low-efficient energy conversion in use. Further, the semiconductor laser pumped solid state laser has been proposed as the improvement for the above points. Approximately 50% of photo-electric conversion efficiency is becoming available and it is though that the generality thereof will further improve.
On the other hand, a solar light pumped laser using solar light as a light source has been also known so far. It is considered that when solar light is used as a pumping light source, laser oscillation could be performed without using any low efficient photo-electric conversion processes that directly consume electricity generated by a fossil fuel. Accordingly, it is considered that a laser apparatus for industrial apparatuses such as a hydrogen generation apparatus and a laser reduction apparatus is possible to use more easily, at a low cost and with a low environmental load. Additionally, electric power generation methods without using a fossil fuel, such as wind power generation, tidal power generation and geothermal power generation, are being put to practical use. For example, though an amount of power generated by the wind power generation extremely varies depending on conditions, however the peak amount of the generated power exceeding 2,000 kWh is possible to provide recently. However, the wind power generation has a large problem in that the amount of the generated power is extremely varied depending on the conditions. Use of a laser reduction apparatus employing a laser that oscillates by the power generated as described above enables to store the energy in a form of magnesium and to supply the energy with a low environmental load.
Further, it was found that a metal ion is generated at the initial process of the decomposition of a metal oxide or the like when laser reduction is performed. The metal ion generated by the laser reduction forms local plasma and could therefore be controlled by using a well-known magnetic confinement system. Further, since metal ions and anion move oppositely to each other in the direction perpendicular to the direction of the magnetic field, it is expected that taking out from the system as an electric current enables energy conversion by photo-electric conversion.    Patent Literature 1: Japanese Patent Laid-Open No. 2003-313001    Patent Literature 2: Japanese Patent Laid-Open No. 2003-226502    Patent Literature 3: Japanese Patent Laid-Open No. 2002-69558    Patent Literature 4: Japanese Patent Laid-Open No. H8-109001    Patent Literature 5: Japanese Patent Laid-Open No. H8-59201    Patent Literature 6: Japanese Patent Laid-Open No. H7-109102    Patent Literature 7: Japanese Patent Laid-Open No. 2004-231466